<?php
/**
* @see https://github.com/laminas/laminas-mail for the canonical source repository
* @copyright https://github.com/laminas/laminas-mail/blob/master/COPYRIGHT.md
* @license https://github.com/laminas/laminas-mail/blob/master/LICENSE.md New BSD License
*/
namespace Laminas\Mail\Protocol;
use Laminas\Validator;
/**
* Provides low-level methods for concrete adapters to communicate with a
* remote mail server and track requests and responses.
*
* @todo Implement proxy settings
*/
abstract class AbstractProtocol
{
/**
* Mail default EOL string
*/
const EOL = "\r\n";
/**
* Default timeout in seconds for initiating session
*/
const TIMEOUT_CONNECTION = 30;
/**
* Maximum of the transaction log
* @var int
*/
protected $maximumLog = 64;
/**
* Hostname or IP address of remote server
* @var string
*/
protected $host;
/**
* Port number of connection
* @var int
*/
protected $port;
/**
* Instance of Laminas\Validator\ValidatorChain to check hostnames
* @var \Laminas\Validator\ValidatorChain
*/
protected $validHost;
/**
* Socket connection resource
* @var resource
*/
protected $socket;
/**
* Last request sent to server
* @var string
*/
protected $request;
/**
* Array of server responses to last request
* @var array
*/
protected $response;
/**
* Log of mail requests and server responses for a session
* @var array
*/
private $log = [];
/**
* Constructor.
*
* @param string $host OPTIONAL Hostname of remote connection (default: 127.0.0.1)
* @param int $port OPTIONAL Port number (default: null)
* @throws Exception\RuntimeException
*/
public function __construct($host = '127.0.0.1', $port = null)
{
$this->validHost = new Validator\ValidatorChain();
$this->validHost->attach(new Validator\Hostname(Validator\Hostname::ALLOW_ALL));
if (! $this->validHost->isValid($host)) {
throw new Exception\RuntimeException(implode(', ', $this->validHost->getMessages()));
}
$this->host = $host;
$this->port = $port;
}
/**
* Class destructor to cleanup open resources
*
*/
public function __destruct()
{
$this->_disconnect();
}
/**
* Set the maximum log size
*
* @param int $maximumLog Maximum log size
*/
public function setMaximumLog($maximumLog)
{
$this->maximumLog = (int) $maximumLog;
}
/**
* Get the maximum log size
*
* @return int the maximum log size
*/
public function getMaximumLog()
{
return $this->maximumLog;
}
/**
* Create a connection to the remote host
*
* Concrete adapters for this class will implement their own unique connect
* scripts, using the _connect() method to create the socket resource.
*/
abstract public function connect();
/**
* Retrieve the last client request
*
* @return string
*/
public function getRequest()
{
return $this->request;
}
/**
* Retrieve the last server response
*
* @return array
*/
public function getResponse()
{
return $this->response;
}
/**
* Retrieve the transaction log
*
* @return string
*/
public function getLog()
{
return implode('', $this->log);
}
/**
* Reset the transaction log
*
*/
public function resetLog()
{
$this->log = [];
}
// @codingStandardsIgnoreStart
/**
* Add the transaction log
*
* @param string $value new transaction
*/
protected function _addLog($value)
{
// @codingStandardsIgnoreEnd
if ($this->maximumLog >= 0 && count($this->log) >= $this->maximumLog) {
array_shift($this->log);
}
$this->log[] = $value;
}
// @codingStandardsIgnoreStart
/**
* Connect to the server using the supplied transport and target
*
* An example $remote string may be 'tcp://mail.example.com:25' or 'ssh://hostname.com:2222'
*
* @param string $remote Remote
* @throws Exception\RuntimeException
* @return bool
*/
protected function _connect($remote)
{
// @codingStandardsIgnoreEnd
$errorNum = 0;
$errorStr = '';
// open connection
set_error_handler(
function ($error, $message = '') {
throw new Exception\RuntimeException(sprintf('Could not open socket: %s', $message), $error);
},
E_WARNING
);
$this->socket = stream_socket_client($remote, $errorNum, $errorStr, self::TIMEOUT_CONNECTION);
restore_error_handler();
if ($this->socket === false) {
if ($errorNum == 0) {
$errorStr = 'Could not open socket';
}
throw new Exception\RuntimeException($errorStr);
}
if (($result = stream_set_timeout($this->socket, self::TIMEOUT_CONNECTION)) === false) {
throw new Exception\RuntimeException('Could not set stream timeout');
}
return $result;
}
// @codingStandardsIgnoreStart
/**
* Disconnect from remote host and free resource
*
*/
protected function _disconnect()
{
// @codingStandardsIgnoreEnd
if (is_resource($this->socket)) {
fclose($this->socket);
}
}
// @codingStandardsIgnoreStart
/**
* Send the given request followed by a LINEEND to the server.
*
* @param string $request
* @throws Exception\RuntimeException
* @return int|bool Number of bytes written to remote host
*/
protected function _send($request)
{
// @codingStandardsIgnoreEnd
if (! is_resource($this->socket)) {
throw new Exception\RuntimeException('No connection has been established to ' . $this->host);
}
$this->request = $request;
$result = fwrite($this->socket, $request . self::EOL);
// Save request to internal log
$this->_addLog($request . self::EOL);
if ($result === false) {
throw new Exception\RuntimeException('Could not send request to ' . $this->host);
}
return $result;
}
// @codingStandardsIgnoreStart
/**
* Get a line from the stream.
*
* @param int $timeout Per-request timeout value if applicable
* @throws Exception\RuntimeException
* @return string
*/
protected function _receive($timeout = null)
{
// @codingStandardsIgnoreEnd
if (! is_resource($this->socket)) {
throw new Exception\RuntimeException('No connection has been established to ' . $this->host);
}
// Adapters may wish to supply per-commend timeouts according to appropriate RFC
if ($timeout !== null) {
stream_set_timeout($this->socket, $timeout);
}
// Retrieve response
$response = fgets($this->socket, 1024);
// Save request to internal log
$this->_addLog($response);
// Check meta data to ensure connection is still valid
$info = stream_get_meta_data($this->socket);
if (! empty($info['timed_out'])) {
throw new Exception\RuntimeException($this->host . ' has timed out');
}
if ($response === false) {
throw new Exception\RuntimeException('Could not read from ' . $this->host);
}
return $response;
}
// @codingStandardsIgnoreStart
/**
* Parse server response for successful codes
*
* Read the response from the stream and check for expected return code.
* Throws a Laminas\Mail\Protocol\Exception\ExceptionInterface if an unexpected code is returned.
*
* @param string|array $code One or more codes that indicate a successful response
* @param int $timeout Per-request timeout value if applicable
* @throws Exception\RuntimeException
* @return string Last line of response string
*/
protected function _expect($code, $timeout = null)
{
// @codingStandardsIgnoreEnd
$this->response = [];
$errMsg = '';
if (! is_array($code)) {
$code = [$code];
}
do {
$this->response[] = $result = $this->_receive($timeout);
list($cmd, $more, $msg) = preg_split('/([\s-]+)/', $result, 2, PREG_SPLIT_DELIM_CAPTURE);
if ($errMsg !== '') {
$errMsg .= ' ' . $msg;
} elseif ($cmd === null || ! in_array($cmd, $code)) {
$errMsg = $msg;
}
// The '-' message prefix indicates an information string instead of a response string.
} while (strpos($more, '-') === 0);
if ($errMsg !== '') {
throw new Exception\RuntimeException($errMsg);
}
return $msg;
}
}